2019 (1) 3

https://doi.org/10.15407/polymerj.41.01.026

Peculiarities of structure formation and the properties of silver-containing polymer composites based on chemically modified melamine-formaldehyde polymer

A.L. Tolstov1, V.F. Matyushov1, D.A. Klymchuk2, E.V. Lebedev1

1Institute of Macromolecular Chemistry NAS of Ukraine

48, Kharkivske shose, Кyiv, 02160, Ukraine; e-mail: a.tolstov@ukr.net

2N.G. Kholodny Institute of Botany NAS of Ukraine

2, Tereshchenkivska str., Kyiv, 01601, Ukraine

Polym. J., 2019, 41, no. 1: 26-33

Section: Structure and properties.

Language: Ukrainian.

Abstract:

Here we have proposed a method of chemical modification of melamine-formaldehyde resins (MFR) and MFR-based polymer materials by reactive isocyanate-terminated oligomers to improve a hydrophilicity and permeability of the polymer matrix. The chemical structure of modified polymer matrices as well as the compositional and physical-chemical characteristics of modified polymers and their composites were studied by FTIR and UV-vis spectroscopy, energy-dispersive X-ray spectroscopy, morphology analysis, conductometry and gravimetry. It was found that introducing the oligomeric modifiers into chemical structure of melamine-formaldehyde polymer during crosslinking process provides a formation of phase-separated polymer systems, reducing cross-links density and increasing sorption capacity of the matrix to polar molecules and ions. As a result, water sorption capacity for chemically modified polymer matrices grows up to 1,1-2,6 times, and relative sorption of Ag+ ions increases from 0,015 (unmodified MFR) to 0,047-0,065 g/g due to increased content of highly polar and coordination-active functional groups. Applying chemically modified melamine-formaldehyde matrices for preparing silver-containing composites via sorption approach allows to produce the polymer materials with gradient silver distribution in bulk. Peculiarities of chemical and phase structure of modified melamine-formaldehyde polymer provide the higher concentration of silver spread deep into a surface layer of the matrix up to 80 мm. The average silver content in a surface layer with a thickness of ~5 мm is about 12 %.

Keywords: melamine-formaldehyde polymer, oligomers, chemical modification, silver, properties.

References

1. Mark H.F. Encyclopedia of Polymer Science and Technology, Hoboken: John Wiley & Sons, Inc., 2004. 1350. ISBN 978-0-470-04610-4.
2. Pat. 4938955 USA, IC7A 61 K 31/74. Antibiotic resin composition. R. Niira, T. Yamamoto, M. Uchida, Y. Fukuoka. Publ. 03.07.1990.
3. Kim S., Kim H.-J. Anti-bacterial performance of colloidal silver-treated laminate wood flooring. Int. Biodeter. Biodegr. 2006, 57: 155-162. DOI: 10.1016/j.ibiod.2006.02.002.
4. Tolstov A.L., Matyushov V.F., Malanchuk O.N. Structure and bactericidal properties of polymer composites based on melamine-formaldehyde polymer and silver nanoparticles formed in situ. Theoret. Experim. Chem. 2014, 50: 181-186. DOI: 10.1007/s11237-014-9363-9.
5. Moawed E.A., Zaid M.A.A., El-Shahat M.F. Methylene Blue-Grafted Polyurethane Foam Using as a Chelating Resin for Preconcentration and Separation of Cadmium(II), Mercury(II), and Silver(I) from Waste Water. Analyt. Lett. 2003, 36: 405-422. DOI: 10.1081/AL-120017699.
6. Sivashankar K., Ranganathan A., Pedireddi V.R., Rao C.N.R. Novel supramolecular organizations in melamine complexes with 4,4′-bipyridyl and silver nitrate. J. Mol. Struct. 2001, 559: 41-48. DOI: 10.1016/S0022-2860(00)00686-4.
7. Massoud A.A., Langer V. Bis(1,3,5-triazine-2,4,6-triamine-kN1)-silver(I) nitrate. Acta Cryst. C. 2009, 65: m198-m200. DOI: 10.1107/S0108270109013110.
8. Yirikoglu H., Gulfen M. Separation and Recovery of Silver(I) Ions from Base Metal Ions by Melamine-formaldehyde-thiourea (MFT) Chelating Resin. Sep. Sci Technol. 2008, 43: 376-388. DOI: 10.1080/01496390701787305.
9. Abd El-Ghaffar M.A., Abdel-Wahab Z.H., Elwakeel K.Z. Extraction and separation studies of silver(I) and copper(II) from their aqueous solution using chemically modified melamine resins. Hydrometallurgy. 2009, 96: 27-34. DOI: 10.1016/j.hydromet.2008.07.008.
10. Ping H., Zhang M., Li H., Li S., Chen Q., Sun C., Zhang T. Visual detection of melamine in raw milk by label-free silver nanoparticles. Food Control. 2012, 23: 191-197. DOI: 10.1016/j.foodcont.2011.07.009.
11. Romanov N.M. Sovremennoe sostoianye yssledovanyi melamynoformaldehydnыkh smol. Plastycheskye massy. 2004, 2: 3-11 [in Russian].
12. Tolstov A.L., Zinchenko O.V., Matyushov V.F. Sorption of Ag+Ions by Polyurethanes Modified by Carbamide or Amino Groups. Theoret. Experim. Chem. 2015, 51: 333-338. DOI: 10.1007/s11237-015-9434-6.
13. Tolstov A.L. Production and physicochemical characteristics of silver-containing polyurethane systems. Theoret. Experim. Chem. 2013, 49: 347-370. DOI: 10.1007/s11237-014-9336-z.
14. Voronov A., Kohut A., Vasylyev S., Peukert W. Mechanism of Silver Ion Reduction in Concentrated Solutions of Amphiphilic Invertible Polyesters in Nonpolar Solvent at Room Temperature. Langmuir. 2008, 24: 12587-12594. DOI: 10.1021/la801769v.
15. Pastoriza-Santos I., Liz-Marzan L.M. Formation and Stabilization of Silver Nanoparticles through Reduction by N,N-Dimethylformamide. Langmuir. 1999, 15: 948-951. DOI: 10.1021/la980984u.